Questions regarding password-based authentication and password management

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4
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3answers
228 views

Automatic login via ssh (no GUI environment installed / no ssh-agent available)?

I have three systems, and I want to have them doing backups between them periodically. The two of them, have Debian Wheezy installed and the other one has Ubuntu 12.04 installed. Only the Ubuntu has a ...
4
votes
3answers
400 views

How to unlock account for public key ssh authorization, but not for password authorization?

The ssh won't let me login, because account is locked. I want to unlock the user on my server for public key authorization over ssh, but do not enable password-ed login. I've tried: # passwd -u ...
4
votes
3answers
2k views

chroot permission denied! But Im root!

I am trying to chroot into an old HD to change a forgotten password, but chroot says permission denied? what gives? I am root! The harddrive I am trying to chroot into is an old version of edUbuntu ...
4
votes
2answers
2k views

/etc/shadow date of last password change—UTC or local time?

man 5 shadow gives the following description of the third field in each line: The date of the last password change, expressed as the number of days since Jan 1, 1970. The value 0 has a ...
4
votes
2answers
209 views

Why rejection of password is much slower than acceptance of it? [duplicate]

In both my Linux and OSX machines when I type in the password to login, a correct password is accepted immediately. However, if I type a wrong password, checking process takes much longer. How is ...
4
votes
1answer
2k views

How to reset password on an encrypted fs?

I've got a laptop which I haven't used since the last summer vacation: I did put Debian 7 on it and used Debian's feature to fully encrypt the disk, besides a tiny bootloader (or a tiny partition) I ...
4
votes
4answers
325 views

Login into a GNU/Linux distribution is taking too long

So, When I try to login with my username and password (in tty), and insert a wrong password, I need to wait around 5 seconds for the system to tell me that the password is wrong. Why the validating ...
4
votes
3answers
428 views

Something like pwgen-win for linux?

Is there some kind of pwd generator for Linux that has a nice GUI and options like this one for Windows? I know that there is pwgen, but as far as I know it does not support mouse/keyboard entropy and ...
4
votes
2answers
200 views

Determining the Password Status of a User

I have a debian box that I connect to via SSH. I have removed the password from the users root, and my personal account using the instructions here, and set up a public/private key pair so I can log ...
4
votes
1answer
468 views

Encrypt word X to /etc/shadow encryption

I've changed my password to X and the shadow file has changed to: ahmad:$1$oYINSKjP$eCkCtJV/2dXerAD57WQPj/:15425:0:99999:7::: I see the encrypted X as $1$oYINSKjP$eCkCtJV/2dXerAD57WQPj/. How can I ...
4
votes
2answers
228 views

Why should you NEVER edit the /etc/shadow file directly?

In another answer here on UNIX & Linux Stack Exchange Michael D Parker wrote, in response to someone saying that doing so was "safe", that:Usually you should NEVER edit the /etc/shadow file ...
4
votes
2answers
223 views

User created without a password behaves as if he had one

Inside one of my scripts, I created an user based on a directory arrangement on another machine. The thing is that this user, created without a password, behaves just as he had one : he has sudo ...
4
votes
1answer
13k views

How to set password for users in AIX using single line command?

Is there any way in which I can set the password for a newly created user account in AIX in a one line command? I don't want to give any prompt to the user. If there is a command, it should set the ...
4
votes
2answers
393 views

Password protecting a system file? (e.g. /etc/resolv.conf)

I am trying to parental control myself by restricting web access via OpenDNS. The OpenDNS account password will be handed to someone trustworthy. Now, I want to put some restriction on the ...
4
votes
1answer
13k views

How to create a user with given password on SuSE from command line?

I need to create bunch of new users with given password. What I want is a script that I would pass the user name of new user and it will create/add the user and set its password. (the password is the ...
4
votes
3answers
2k views

scp: localhost password not accepted

I'm attempting to copy a public key to a remote server. I'm logged in locally as [localname] and the key resides locally at ~/.ssh/. I'm also ssh'd into [remote.com] as [remotename], and attempting to ...
4
votes
2answers
557 views

Is it possible (and a good idea) to do `pw lock root` on FreeBSD?

I have set up sudo on my FreeBSD server. As I now never want to log in as root anymore, I was wondering whether I should do sudo pw lock root. My questions are: Is this possible, without forever ...
4
votes
1answer
91 views

Is it safe for my ssh user to be given passwordless sudo for `apt-get update` and `apt-get upgrade`?

I have an SSH standard user account on my personal server, and it has sudo access (via its password). I ssh in using a public key, so I don't have to type in the account password to log in. Is it ...
4
votes
2answers
9k views

Avoid “Authentication token manipulation error” on password change

I'm implementing a security policy that will force the users to introduce stricter passwords when they change their own: The /etc/pam.d/passwd configuration file is: #%PAM-1.0 auth include ...
4
votes
1answer
27k views

How to lock users after 5 unsuccessful login tries?

How to lock users after 5 unsuccessful login tries? I gathered a few distributions/versions to how to do it, but I can't test it. RHEL4: by adding the: auth required ...
4
votes
1answer
364 views

How to change the forgotten root password?

I am very new to Debian linux, I forgot my root password...actually I think I know what it is because it is the same password I have for pretty much everything but in the Terminal in tell me "Sorry, ...
4
votes
3answers
271 views

Randomise or shred memory of an application

Is it possible to randomise or shred memory of a particular application just after its life ends, or better, whenever it deallocates some memory? A command-line utility like this would be perfect: ...
4
votes
1answer
66 views

Change the root password of a Linux image

I'm building a jessie build of Debian. Passwords are saved in /etc/shadow in the build tree, but they are salted obviously so I cannot change it just by editing the file. If this was my installed ...
4
votes
1answer
99 views

Self-contained password manager with CLI [closed]

I'm looking for a password manager that has the following properties: The manager is entirely self-contained. I take and install a directory on a thumbdrive and execute from that drive. It should ...
4
votes
2answers
2k views

How could I eliminate Kerberos for passwd?

When I issue a command to change my password like this: sudo passwd huahsin The system prompt me: Current Kerberos password: I don't know what I have done to the system configuration, how could I ...
4
votes
1answer
1k views

Why ssh-copy-id prompts for the local user password three times?

Noticed from my previous question that when trying to copy an SSH public key to a remote host via ssh-copy-id, I am prompted for the local user password three times: ssh-copy-id myuser@myserver ...
4
votes
2answers
2k views

Two-step remote ssh without password

I'm looking to ssh from my localhost to a remote server, and from there to a remote computer. I currently have it set up so that the remote computer and remote server have passwordless ssh-ing set up ...
4
votes
2answers
110 views

how to prevent a buffer from swap

this question is specific to Unix and Linux. but it is programming and security, too. my program will get a clear password or decryption key by one of a few ways (decrypting a password file, asking ...
4
votes
2answers
87 views

SSH password requested when in Tmux

When I connect to my remote machine I do authenticate using a rsa key (I think is rsa, don't remember). If I do ssh from a regular shell I get logged on the machine without a password. However if I ...
4
votes
1answer
278 views

Can linux use a mix of SHA-1 and CRYPT passwords?

We have an automated sync-routine that uses useradd to create new users on a Ubuntu 10.04 machine. The application launching the routine provided both username and CRYPT-encrypted password. However, ...
4
votes
1answer
67 views

password store storing some passwords in plain text

I red about the password management program pass in a question on this forum and decided to try it. I installed from the download page (tarball 1.6.3). I created some test entries and then some real ...
4
votes
2answers
131 views

Using $ in a password

Lets assume that password of my server is Abcd$1234 I am trying to ftp a file from other server to my server using the following in shell script ftp -inv (IP) << EOF user Username Abcd$1234 ...
4
votes
2answers
8k views

Deleting a samba user: pbdedit vs. smbpasswd, what's the difference?

What is the difference between $ pdbedit -x and $ smbpasswd -x to delete samba users?
4
votes
1answer
153 views

Where are passwords stored and how are they encrypted in OS X?

I know that on a Linux system passwords are stored in /etc/shadow and are salted and encrypted using a one way hashing algorithm like MD5, SHA-256 or SHA-512. It looks like there is no /etc/shadow ...
4
votes
1answer
1k views

Validate AIX Password for root from script

Looking for a way in a shell script to validate the password for for root on an (AIX) matches a standardized plain text password. This query is similar to another one on this site. I have access to ...
4
votes
1answer
2k views

Password expiry in Samba v3.0

I'm trying to setup a Samba server which asks new users to change their password on their first login and makes passwords expire after 90 days. I was able to setup the 90 days expiry date but the ...
4
votes
1answer
388 views

how to verify if root password changed correctly

I have an OpsWare task, that changes root passwords on a massive number of servers, by replacing the root's password hash in /etc/shadow file. I need a script of some sort, which preferably runs ...
3
votes
5answers
2k views

Encrypt a password the same way mysql does

I've created a user ... but forgotten the password mysql> create user 'blayo'@'%' identified by 'right'; Which Linux command line tool can encrypt the password the same way mysql 5.5 does ? ...
3
votes
4answers
5k views

What command should I run after making changes to /etc/passwd file

I have made some changes to /etc/passwd file ,now I wanted to see if the effect of changes taken place or not .What command should I run for that. For example after making change to ...
3
votes
2answers
3k views

Second field in /etc/shadow

If the second field of the /etc/shadow file is set to !!, does it mean that the account is disabled? Or does it mean that the account is active with no password assigned?
3
votes
3answers
239 views

How to mask passwords in 'watch' command?

I am using watch to monitor the progress of a MySQL replication slave. The way I have it set up now, the password shows up in the header of the watch output. I am not exceedingly worried that someone ...
3
votes
2answers
1k views

show entered new password in unix “passwd” command

Is is possible to run the passwd command with an option to show the newly entered passwords? By default it doesn't show what I type and I don't want this. [dave@hal9000 ~]$ passwd Changing password ...
3
votes
4answers
2k views

Why can't I echo the password to fetchmail?

I'm trying to configure a fetchmail. Before I deal with the syntax of fetchmailrc ( I discovered that the level of bugginess of a problem is synergistic with the number of different aspects of the ...
3
votes
3answers
506 views

Changing user password through GUI app

I was making a GUI application to manage users and groups in Linux! I'm done with the part where it creates a new user, but stuck with the part where it gives the newly created user a new password. ...
3
votes
2answers
4k views

How to Create a Encrypted Password

I want to know how can I create a encrypted password in Ubuntu 14.04 TLS. Tried this: makepasswd --crypt-md5 password_here Did not worked for me throwing this Error sysadmin@localhost:~$ ...
3
votes
3answers
12k views

Lost password for a user on a Linux Server: How reset it?

On a Server an user 16040 has lost his password. I have password for root but don't have password for user 16040. How can I reset his password? With passwd 16040, unix ask me current password that I ...
3
votes
1answer
814 views

sudo command executes without prompting for password

For some reason, I suddenly do not need to enter the password when issuing sudo some_cmd. Entered command just runs without ever prompting password, even if I am not logged in as user root. Commands ...
3
votes
4answers
2k views

passing passwords to a script

I want to scp a file to a remote host, and from there, run a command on the file, and exit the remote session. If I write a usual script, call scp and then ssh, I am prompted to enter two passwords. ...
3
votes
2answers
4k views

Ubuntu password policy

I want to set the system-wide password policy on an Ubuntu 12.04 LTS server. Googling around, a lot of people point to this (very old) document: ...
3
votes
2answers
619 views

How to make a folder request root password to view execute?

I am running Ubuntu 10.04 LTS. I want to use my laptop to play music in a party. MY screensaver does not need a password to deactivate. I would like to allow people to use my computer to play the ...